A diffractive optical element (DOE) may be used for directing a beam. For example, a DOE, such as a diffractive lens, a spot array illuminator, a spot array generator, a Fourier array generator, and/or the like, may be used to split a beam, shape a beam, focus a beam, and/or the like. A DOE may be integrated into a multicast switch, a wavelength selective switch, a gesture recognition system, a motion sensing system, and/or the like.
A multi-level surface relief profile may be selected for a surface relief DOE. For example, a two-level (sometimes termed “binary”) surface relief profile may be selected for the surface relief DOE. The multi-level surface relief profile may be selected to approximate a continuous surface relief profile and to enable use of a photolithographic procedure and/or an etching procedure to manufacture the DOE. A two-level thin film stack may be used to create a single order binary DOE, such as a diffractive lens. Some materials used for DOEs may require an etch depth of greater than a threshold, thereby resulting in a threshold etch time to manufacture the DOE.